System and method for supervising calls in the exchange

• US 6,026,147 A
• Filed: 06/04/1998
• Issued: 02/15/2000
• Est. Priority Date: 06/18/1997
• Status: Expired due to Term

• Current Assignee: LG-Ericsson Company Limited (Telefonaktiebolaget LM Ericsson)
• Original Assignee: LG Information & Communications Ltd. (LG Corporation)
• Inventors: Yeo, Nam Soo
• Primary Examiner(s): Loomis, Paul
• Assistant Examiner(s): BARNIE, REXFORD N
• Application Number:
  US09/090,238
• Time in Patent Office: 621 Days
• Field of Search: 379/7, 379/9, 379/10, 379/18, 379/34, 379/198, 379/201, 379/6, 379/12, 379/22, 379/26, 379/35, 379/29, 379/265, 379/266, 379/309
• US Class Current: 379/35
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls

Abstract

A call supervisory system in the exchange includes: a trunk card device (TCD) connected to a trunk card of an external system via a control trunk line (CTL); a device control unit (DCU), as a lower level processor, for controlling the TCD; a man machine interface unit (MMIU) matched with the external system for switching data and managing a password; a call trace and path setup control unit (CTCU) for controlling the call supervisory system according to demands of the external system received through the MMIU and informing a result of the relevant control to the external system via the MMIU; a number translation unit (NUTU) for translating and managing the exchange number when processing calls according to the control of the CTCU; a call trace and path setup unit (CTSU) for setting up call supervision and a call path according to the control of the CTCU; a call management unit (CMU) for performing a call process function of the exchange, sending a call supervision control flag to NUTU, and informing occurrence of call process events to the CTSU; a fault control unit (FACU) for controlling fault in the call supervisory system and informing contents of the fault to the external system via the MMIU; and a telephony device maintenance unit (TDMU) for controlling maintenance and repair of speech path equipment according to the control of the FACU.

Claims

1. A call supervisory system in an exchange comprising:

a trunk card device connected to a trunk card of an external system via a control trunk line;

device control unit, as a lower level processor, for controlling the trunk card device;

a man machine interface unit matched with the external system for switching data and managing a password;

a call trace and path setup control unit for controlling the call supervisory system according to demands of the external system received through the man machine interface unit and informing a result of the relevant control to the external system via the man machine interface unit;

a number translation unit for translating and managing an exchange number according to the control of the call trace and path setup control unit when processing calls;

a call trace and path setup unit for setting up call supervision and a call path according to the control of the call trace and path setup control unit;

a call management unit for performing a call process function of the exchange, sending a call supervision control flag to the number translation unit, and informing occurrence of call process events to the call trace and path setup unit;

a fault control unit for controlling fault in the call supervisory system and informing contents of the fault to the external system via the man machine interface unit; and

a telephony device maintenance unit for controlling maintenance and repair of speech path equipment according to the control of the fault control unit.

2. A call supervisory method in an exchange comprising the steps of:

checking whether a call supervisory system is operative in response to an operation starting command signal;

grouping control trunk lines (CTL) into specified CTL units according to a grouping command signal;

identifying registration/non-registration and conformity/unconformity of each call supervised object and performing registration, removal, change of information, or inquiry with respect to each call supervised object; and

performing call monitoring and tapping with respect to each call supervised object.

3. The method according to claim 2, further comprising the step of identifying normality of a password according to a password changing command signal and newly registering a new password in a memory.

4. The method according to claim 2, further comprising the step of clearing each memory stored call supervisory information and prefix or subscriber'"'"'s call supervision and CTL management information and ending operation of the call supervisory system.

5. The method according to claim 4, wherein the call supervisory information contains a telephone number of a subscriber occurred a transmitting/receiving signal, current time, subscriber'"'"'s registration rank, priority order, and CTL used during the call tapping.

6. The method according to claim 2, wherein each command signal consists of contents of command and a header including an identification number of each call supervisory system, length of the contents of command, command code, and a password.

7. The method according to claim 2, wherein a transmission message for informing results of performing each step to an external system contains contents of command and a header including an identification number of each call supervisory system, length of the contents of command, and message code.

8. The method according to claim 7, wherein a header format of the call supervisory information of the transmission messages contains a call identifier which is properly given to each subscriber or prefix registered for call supervision when performing the registration for the call supervision.

9. The method according to claim 2, wherein the step of checking whether the call supervisory system is operative comprises the steps of:

performing initialization in response to the operation starting command signal and registering a password in a memory;

setting an operation flag of the call supervisory system and informing a demand of operation start of the call supervisory system;

clearing each memory after identifying whether or not the call supervisory information is stored in each memory and preparing for performing the registration for the call supervision according to a demand of an external system; and

identifying whether or not fault occurs in the call supervisory system and informing to the external system, contents of the fault or normality in the start operation.

10. The method according to claim 2, wherein the step of grouping the CTLs comprises the steps of:

checking normality of a password received from an external system in response to the grouping command signal;

registering a demand of grouping the CTLs in a CTL management local memory and a CTL management database; and

grouping each CTL into each specified CTL group and informing a result of the grouping to the external system.

11. The method according to claim 2, wherein the step of grouping the CTLs further comprises the step of reading all the CTLs contained in the CTL group to be inquired from the CTL management local memory and transmitting them to the external system according to a demand of the external system or when inquiring a number of a CTL belonging to a particular CTL group.

12. The method according to claim 2, wherein the step of performing registration, removal, change of information, or inquiry with respect to the call supervised object comprises the steps of:

identifying normality of a password received from an external system in response to a command signal related to the call monitored and tapped object;

checking the call monitored and tapped object to find that the object is a subscriber to other system or to the call supervisory system concerned and identifying the registration/non-registration and conformity/unconformity of a relevant prefix or subscriber; and

performing the registration, removal, change of information, or inquiry with respect to the call supervisory information in a call monitoring/tapping management local memory and a call process database according to the command signal related to the call monitored and tapped object and transmitting a performed result to the external system.

13. The method according to claim 2, wherein contents of the command signal related to the call monitored and tapped object comprise a type of each registered object, conditional number, digit(s) of subscriber'"'"'s telephone number or the prefix, call supervision control method, CTL group number, and priority order.

14. The method according to claim 2, wherein the step of performing call monitoring and tapping comprises the steps of:

checking a call supervision registration flag and informing information related to occurrence of each call process event; and

identifying a fact of registration for the call supervision from a memory and transmitting the call supervisory information to an external system by events.

15. The method according to claim 2, wherein the step of performing call monitoring and tapping further comprises the steps of:

inquiring of a memory to identify the registration for call supervision according to a call tapping command signal or when there occur call process events of busy state and answer for receiving signal;

checking whether subscriber'"'"'s line is busy and identifying a call simultaneous monitoring and tapping registration rank;

allocating a call mixer, CTL, and switch resource and resetting calls in the call mixer; and

performing tapping of calls after setting paths of each call in the call mixer and CTL and transmitting a result of the tapping to the external system.

16. The method according to claim 15, wherein the call tapping command signal includes a call identifier.

17. The method according to claim 15, wherein the call path is established as a three-party talking type using conference talking equipment and is designed to have one-way feature.

18. The method according to claim 2, further comprising the step of canceling the paths of each call in the call mixer and CTL according to a call tapping canceling command signal or when there occurs a call process event of call disconnection, withdrawing the allocated call mixer, CTL, and switch resource, and informing call tapping cancellation to the external system.

19. The method according to claim 18, wherein the call tapping canceling command signal includes a call identifier and CTL number.

20. The method according to claim 2, wherein the step of ending operation of the call supervisory system comprises the steps of:

identifying normality of a password received from an external system in response to the operation ending command signal;

informing a demand of ending the operation of the call supervisory system after clearing the operation flag; and

clearing a system fault detection operation flag, call supervisory information, prefix'"'"'s call supervision management information, and subscriber'"'"'s call supervision and CTL management information stored in each memory and informing a result of the ending operation to the external system.